What is this medicine?
ISONIAZID (eye soe NYE a zid) is used to prevent or to treat tuberculosis.
How should I use this medicine?
Take this medicine by mouth with a glass of water. Follow the directions on the prescription label. Take this medicine on an empty stomach, at least 30 minutes before or 2 hours after food. Do not take with food. Use a specially marked spoon or container to measure each dose. Ask your pharmacist if you do not have one. Household spoons are not accurate. Take your medicine at regular intervals. Do not take it more often than directed. Take all of your medicine as directed even if you think you are better. Do not skip doses or stop your medicine early. Skipping doses may make the TB resistant to this medicine and other medicines. Do not stop taking except on your doctor's advice.
Talk to your pediatrician regarding the use of this medicine in children. While this drug may be prescribed for selected conditions, precautions do apply.
What side effects may I notice from receiving this medicine?
Side effects that you should report to your doctor or health care professional as soon as possible:
allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
changes in vision or eye pain
fever, sore throat
hallucination, loss of contact with reality
loss of appetite
pain, tingling, numbness in the hands or feet
redness, blistering, peeling or loosening of the skin, including inside the mouth
unusually weak or tired
yellowing of the eyes or skin
Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):
What may interact with this medicine?
Do not take this medicine with any of the following medications:
MAOIs like Carbex, Eldepryl, Marplan, Nardil, and Parnate
This medicine may also interact with the following medications:
medicines for diabetes
medicines for fungal infections like ketoconazole and itraconazole
medicines for seizures like carbamazepine, phenobarbital, phenytoin, valproic acid
What if I miss a dose?
If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.
Where should I keep my medicine?
Keep out of the reach of children.
Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F). Protect from light. Keep container tightly closed. Throw away any unused medicine after the expiration date.
What should I tell my health care provider before I take this medicine?
They need to know if you have any of these conditions:
if you frequently drink alcohol-containing beverages
tingling of the fingers or toes, or other nerve disorder
an unusual or allergic reaction to isoniazid, other medicines, foods, dyes or preservatives
pregnant or trying to get pregnant
What should I watch for while using this medicine?
Visit your doctor or health care professional for regular check ups. You will need blood work done regularly.
You may need to take vitamin supplements while on this medicine. Talk to your doctor about the foods you eat and the vitamins you take. Avoid antacids for 2 hours before and after taking a dose of this medicine.
Alcohol may interfere with the effect of this medicine. Avoid alcoholic drinks.
If you are diabetic check your blood sugar as directed. Also, you may get a false-positive result for sugar in your urine. Talk with your doctor.